Hassler Whitney

Hassler Whitney (March 23, 1907 – May 10, 1989) was an American mathematician. He was one of the founders of singularity theory, and did foundational work in manifolds, embeddings, immersions, and characteristic classes. Whitney's earliest work, from 1930 to 1933, was on graph theory. Many of his contributions were to the graph-coloring, and the ultimate computer-assisted solution to the four-color problem relied on some of his results. His work in graph theory culminated in a 1935 paper, where he laid the foundations for matroids, a fundamental notion in modern combinatorics and representation theory. Whitney's lifelong interest in geometric properties of functions also began around this time. His earliest work in this subject was on...